MEMS driving device, electronic apparatus, and MEMS driving method

Abstract

A spectroscopic measurement apparatus includes a fixed substrate, a movable substrate, and a wavelength variable interference filter which includes an electrostatic actuator for changing the gap dimension between the substrates, a vibration disturbance detection unit which detects vibration added to the wavelength variable interference filter, and a bias driving unit which applies a feed-forward voltage based on a detected value of the vibration disturbance detection unit to the electrostatic actuator.

What is claimed is: 
     
       1. An MEMS driving device comprising:
 an MEMS element that includes a pair of substrates and an electrostatic actuator which changes a gap dimension between the pair of substrates, wherein the electrostatic actuator includes a bias actuator and a control actuator; 
 a vibration detection unit that detects vibration which is added to the MEMS element; and 
 an actuator control unit that (i) adjusts a feed-forward voltage applied to the electrostatic actuator by adding or subtracting a prescribed value to or from a bias voltage, wherein the prescribed value is based on a detected value of the vibration detection unit, and (ii) applies a feed-back voltage to the electrostatic actuator based on the gap dimension between the pair of substrates, wherein: 
 the feed-back voltage is a voltage that adjusts the gap dimension between the pair of substrates during a feedback control and the feed-forward voltage is a voltage that (i) offsets vibration during the feedback control and (ii) controls a sensitivity of the control actuator based on the bias voltage, and 
 the actuator control unit applies the feed-forward voltage to the bias actuator and applies the feed-back voltage to the control actuator. 
 
     
     
       2. The MEMS driving device according to  claim 1 , further comprising:
 a base substrate to which a part of the MEMS element is fixed, 
 wherein the vibration detection unit detects vibration of the MEMS element with regard to the base substrate. 
 
     
     
       3. The MEMS driving device according to  claim 2 ,
 wherein an end of at least one of the pair of substrates is fixed to the base substrate, and 
 wherein the vibration detection unit detects vibration at a free end on a side which is opposite to the end of the substrate. 
 
     
     
       4. The MEMS driving device according to  claim 2 ,
 wherein at least one of the pair of substrates includes a first electrode which faces the base substrate, 
 wherein the base substrate includes a second electrode which faces the first electrode, and 
 wherein the vibration detection unit detects the vibration based on an electrostatic capacity between the first electrode and the second electrode. 
 
     
     
       5. The MEMS driving device according to  claim 1 ,
 wherein the MEMS element is a wavelength variable interference filter that includes a pair of reflection films which are provided on surfaces of the pair of substrates facing each other, and that selects and emits light having a prescribed wavelength from incident light which is incident to the pair of reflection films facing each other. 
 
     
     
       6. An electronic apparatus comprising:
 an MEMS driving device including:
 an MEMS element that includes a pair of substrates and an electrostatic actuator which changes a gap dimension between the pair of substrates, wherein the electrostatic actuator includes a bias actuator and a control actuator; 
 a vibration detection unit that detects vibration which is added to the MEMS element, and 
 an actuator control unit that (i) adjusts a feed-forward voltage applied to the electrostatic actuator by adding or subtracting a prescribed value to or from a bias voltage, wherein the prescribed value is based on a detected value of the vibration detection unit, and (ii) applies a feed-back voltage to the electrostatic actuator based on the gap dimension between the pair of substrates; and 
 
 a control unit that controls the MEMS driving device, wherein: 
 the feed-back voltage is a voltage that adjusts the gap dimension between the pair of substrates during a feedback control and the feed-forward voltage is a voltage that (i) offsets vibration during the feedback control and (ii) controls a sensitivity of the control actuator based on the bias voltage, and 
 the actuator control unit applies the feed-forward voltage to the bias actuator and applies the feed-back voltage to the control actuator.